Category: Retro PC Projects

Installing a Tseng Labs ET4000 for 70Hz at 640x480 or 800x600 in Windows 3.11

Published on: 2025-03-02

A Tseng Labs ET4000 graphics card with 1MB of video memory is installed in my 386 system, making it an excellent choice for a 386 or 486 setup in general. Compared to the Trident 8900 or Cirrus Logic GD542x series, which were released around the same time, the ET4000 was noticeably faster for DOS games. This ensures excellent 2D gaming performance.

Under DOS, the default refresh rate was always 70Hz. However, in Windows, the display was limited to 60Hz. To achieve the correct refresh rate in Windows, the appropriate drivers are required.

The best results were achieved using drivers from Vogonsdrivers, available at: Download ET4000 Driver.

Driver Installation

The ZIP file was extracted on a Mac, and the files were then transferred to the 386 system using a floppy disk. The driver can be installed through the Windows setup utility.

Installation Steps:

• Extract the ZIP file on a modern system.
• Transfer the extracted files to the 386/486 system using a floppy disk.
• Run the Windows setup utility to install the driver.

(Fig. 1: Windows Setup in progress)

(Fig. 2: Display selection - scroll down to install a driver)

(Fig. 3: Specify path to the driver)

Selecting the Graphics Mode

After installation, the appropriate graphics mode can be selected:

(Fig. 4: Selecting a new display driver mode)

(Fig. 5: Restarting Windows)

Enabling 70Hz in Windows 3.11

To achieve 70Hz in Windows 3.11, the "VMODE.COM" utility is required. This tool can be downloaded from forum.classic-computing.de (vmode.zip).

The VMODE.COM utility is used to adjust the video mode and refresh rate settings of Tseng Labs graphics cards. The commands below switch the video mode to ensure a stable 70Hz refresh rate in Windows 3.11:

    VMODE.COM 72M
    VMODE.COM 72H

Since I couldn't find any official documentation for these specific VMODE.COM settings, these values were determined through trial and error. (The in-program-help wasn't really helpful.) If different hardware configurations behave differently, adjustments might be required.

To automate this process, these commands can be added to the autoexec.bat file:

(Fig. 6: Editing autoexec.bat for automation)

Final Result

After following these steps, Windows will now run at 70Hz:

(Fig. 7: Windows running at 70Hz)

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